Hi folks a newbie here. The guys from Pirate 4x4 sent me over.

Here is the deal. I often pull my Jeep and trailer. About 7000 lbs or so.

Running an 02 2500HD as my DD/tow rig. Fitted out with the 6.0/4L80 and the typical 4.10 gears. Cognito leveling kit and the 6 Bilsteins.

Several years ago I did the Super Chip handheld and changed the timing curve, played a little with the shift point/firmness. Worked ok.

From the 265 tires I moved up to 285`s. A bit taller tire that cuts my cruisng RPM down to where I am just barley into the torque curve. Just over 2000 RPM @ 70. But helps to fill the wheelwell better then the 265`s.

What I want to to be able to get a bit more low end. Say 1500 to 2500 out of it. Like I said, at 70 it is turning just over 2000 RPM. Seems to just getting into the torque curve. Slowing down to 65 it actually gets worse mileage as the trans is always downshifting on any little hill. So a bit more torque in the low range would help out a bunch. Know the tire size isnt helping.

In a perfect world I`d put some 4.56`s or even 4.88`s in it. Do not think that is going to work out with the 4x4.

A ECM tune might be an option but I have to wonder how much tuning can be down when the engine is just short of lugging now

Now with almost 100,000 miles of well cared for miles. I can`t see changing a cam or swapping heads etc. Would seem that the engine would need to be freshened up to make it worthwhile ?? Or maybe the NBS engines have a decent life and if cared for will run many a mile ?


Seems it would make more sense to :

1. Find another 6.0 and freshen it up. Then add to it in order to make low/midrange power. Cam, heads, exhaust ? What am I looking for ?

2. A GM crate motor. Which one ?

3. Move up to an 8.1 and swap one of those in.

4. BB crate motor ?

Course the trans would be rebuilt also. Would like to get all the parts ready and do an engine/trans swap rather then tie my junk up for the time it takes to do the rebuild.

What do you folks think ?

THANKS !!!

 

I would try a 400 LS crate motor that scoggin dickey sells, and if that doesn't work many guys on the boards love the TVS superchargers or even a STS turbo.

But I would still re-gear your truck to get the rpms up a bit.

 

The rear gear will cost alot with the 4 wheel drive! And FI is expensive!

Whats the budget? Cam swaps are easy enough and cheaper than rearing both axles. Plus a custom tune and you'll be set.

 

a custom tune will work wonders!! get with wheatley performance >>>>>>>>>>>>>>>>
and 100k aint nothing for these new motors, a mild cam swap will work great...

 

Go back to smaller tires.

You must live where its flat, our 6.0 hates life with 7K lbs behind it. our truck is 100% stock, crew, auto, 4:10: Im pretty sure at 70 its turning like 2800 rpms. that 2000 rpms with those tires would make me think you 373's Only reason i say that is we have 8.1L with 255-85-16's (33.3 OD) with 3:73 gears and at 73 mph its turning 2000 rpms. 80 2200 rpms and thats with the spedo correction.

Bottom line is the 6.0L motor is a good motor, But the cam & heads dont match up. Thats why its dead down low and pulls like crazy (for a stock turck) from 3500 to 6000 rpms. The 8.1L is a different beast. it pulls from about 1600 to 3800 then its like it has a asthma attach. Also i dont think you can just drop in a 8.1L i had two broken motor mounts. GM shipped the one for a 6.0L and they dont fit the factory holes for the 8.1L...

Only cheap think i can think of is getting some one to do a torqe management delete and drive line protection delete on the truck. That way you will 100 % of the power you ask for.

Also keep in mind fuel. the 8.1L burban gets 10mpg freeway no trailer, where as the 6.0 gets 9 mph freeway with 10K lbs behind it. I think there is something wrong with the suburban..

 

Headers and a Wheatley tune should make a very nice gain down low at the range where you tow.

 

I also agree that a tune would help. My car picked up a lot down low from my tune. My current cam is not really for towing, but the adjustments I made to the timing downlow turned the cam into a really nice package for what I do with the truck.